Smoke detector



FIG. 1 is a bottom view in plan showing our new design;

FIG. 2 is a top view in plan thereof;

FIG. 3 is a left side view in elevation thereof;

FIG. 4 is a rear view in elevation thereof;

FIG. 5 is a right side view in elevation thereof;

FIG. 6 is a left front perspective view from below thereof; and,

FIG. 7 is a front view in elevation thereof. 

The ornamental design for a smoke detector, as shown and described. 